So this cat gives me these two cans, (missing labels), and tells me that they are malt extract, and that I should make beer out of em. I do not know a damn thing about them. I plan on getting my gear ready and just wingin it. I have very little experince with extract brews, however. So I am unsure as to how to prepare for this most mysterious of brew days. Will light and dark extracts look very different? If they are incongruous can I put em together? What kind of shelf life does the stuff have anyhow?